grounder vs groundball

grounder and groundball both are nouns.

Word	Noun	Adjective	Verb	Adverb
grounder	Yes	No	No	No
groundball	Yes	No	No	No

As nouns, grounder and groundball are synonyms defined as:

Other synonyms of grounder include ground ball, hopper.

grounder (noun)	groundball (noun)
(baseball) a hit that travels along the ground	(baseball) a hit that travels along the ground